CELL MASSES IN THE FOREBRAIN 415 
Medial large-celled nucleus. In sections through the rostral 
part of the amygdaloid complex the small-celled mass is covered 
basally by a rounded cap consisting almost wholly of neuropile 
(figs. 16, 42), only a few medium sized cells being imbedded in it. 
This neuropile is formed by the interlacing stria medullaris, 
lateral olfactory tract and olfactory radiations as above de- 
scribed. As the sections are followed caudally the cells in this 
neuropile increase in number and size until a conspicuous nucleus 
forms the basal portion of the complex (figs. 15, 48). This is the 
condition in sections which pass through the caudal border of the 
stria medullaris. Just caudal to this (figs. 14, 44) the temporal 
horn of the ventricle penetrates this nucleus. Farther cau- 
dally the large cells are all found in the lateral or amygdaloid wall 
of the ventricle while the hippocampal formation and fimbria 
appear in the medial wall. The large-celled nucleus lies ventral 
to the tail of the caudate nucleus. This is the region in which 
the tail of the caudate merges with the small-celled nucleus of 
the lateral olfactory tract. Following the sections caudad, 
the caudate rapidly diminishes and the large-celled nucleus 
spreads farther dorsad in the large ventricular ridge (figs. 13, 45). 
At the same time the nucleus of the lateral olfactory tract 
grows smaller and appears as a rather dense mass of cells near the 
amygdaloid fissure. Now there appears in the ventral wall 
between this and the hippocampus an area of scattered cells 
which on being followed further caudad is found to belong to 
the general pallium (which see). By the time this condition 
is reached the caudate has entirely disappeared from the sections 
and the large-celled nucleus has spread dorsad to the level of the 
dorsal branch of the middle ventricular groove. Here this nu- 
cleus constitutes a ventricular layer of large cells rather closely 
packed but not arranged in clusters as are the cells of the dorsal 
part of the dorsal ventricular ridge. Further from the ventricle 
the lower part of the ridge is filled by the same irregularly placed 
cells as are found in the dorsal part. Both these and the ventric- 
ular layer of large cells merge with the general pallium in the 
ventral wall. The ventricular layer representing the large- 
